The present invention relates to ball bumpers for a ball rolling game and, in particular, to a slingshot-type bumper assembly for an electromechanical pin ball game. A slingshot-type bumper assembly typically includes an elastic band tensioned around a plurality of posts a slight distance above the playfield board and adapted for engagement by a rolling pin ball. In order to accelerate the ball as it rebounds from the resilient band, there is also provided a kicker apparatus which is actuated in response to impact of the ball on the resilient band for triggering a kicker into engagement with the inner side of the band to impart a propelling force to the pin ball which is substantially greater than the force which could have been imparted by the deflected band itself.
Typically, the kicker apparatus includes a solenoid mounted vertically beneath the playfield board and having its plunger connected to one end of a crank, the other end of which projects above the playfield board for engagement with the elastic band. An actuator is disposed in engagement with the band for movement thereby when a ball impacts on the band to close a switch for actuating the solenoid pivotally to move the kicker crank into engagement with the band.
A drawback of this type of kicker apparatus is that, because the kicker crank moves pivotally it is inclined at an acute angle to the playfield board at the point of impact with the resilient band and therefore imparts to the band and the ball a force which is directed downwardly toward the playfield board. This has the disadvantageous results of tending to impart spin or English to the pin ball and producing excessive wear of the playfield board immediately adjacent to the elastic band.
One type of kicker assembly, manufactured by the Bally Corporation, has attempted to overcome these disadvantages by orienting the drive solenoid parallel to the playfield board and having it reciprocate a drive arm rather than pivot a crank. While this avoids the problem of imparting a downward kicking force to the ball, it introduces another problem of wear and inefficient operation of the solenoid, the plunger of which will now lie on its side in frictional engagement with the solenoid core bushing.